mirror of
https://github.com/darlinghq/darling-gdb.git
synced 2024-12-05 10:57:57 +00:00
559 lines
19 KiB
Plaintext
559 lines
19 KiB
Plaintext
@c Copyright 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000, 2003, 2004
|
|
@c Free Software Foundation, Inc.
|
|
@c This is part of the GAS manual.
|
|
@c For copying conditions, see the file as.texinfo.
|
|
@ifset GENERIC
|
|
@page
|
|
@node M68K-Dependent
|
|
@chapter M680x0 Dependent Features
|
|
@end ifset
|
|
@ifclear GENERIC
|
|
@node Machine Dependencies
|
|
@chapter M680x0 Dependent Features
|
|
@end ifclear
|
|
|
|
@cindex M680x0 support
|
|
@menu
|
|
* M68K-Opts:: M680x0 Options
|
|
* M68K-Syntax:: Syntax
|
|
* M68K-Moto-Syntax:: Motorola Syntax
|
|
* M68K-Float:: Floating Point
|
|
* M68K-Directives:: 680x0 Machine Directives
|
|
* M68K-opcodes:: Opcodes
|
|
@end menu
|
|
|
|
@node M68K-Opts
|
|
@section M680x0 Options
|
|
|
|
@cindex options, M680x0
|
|
@cindex M680x0 options
|
|
The Motorola 680x0 version of @code{@value{AS}} has a few machine
|
|
dependent options:
|
|
|
|
@table @samp
|
|
|
|
@cindex @samp{-l} option, M680x0
|
|
@item -l
|
|
You can use the @samp{-l} option to shorten the size of references to undefined
|
|
symbols. If you do not use the @samp{-l} option, references to undefined
|
|
symbols are wide enough for a full @code{long} (32 bits). (Since
|
|
@code{@value{AS}} cannot know where these symbols end up, @code{@value{AS}} can
|
|
only allocate space for the linker to fill in later. Since @code{@value{AS}}
|
|
does not know how far away these symbols are, it allocates as much space as it
|
|
can.) If you use this option, the references are only one word wide (16 bits).
|
|
This may be useful if you want the object file to be as small as possible, and
|
|
you know that the relevant symbols are always less than 17 bits away.
|
|
|
|
@cindex @samp{--register-prefix-optional} option, M680x0
|
|
@item --register-prefix-optional
|
|
For some configurations, especially those where the compiler normally
|
|
does not prepend an underscore to the names of user variables, the
|
|
assembler requires a @samp{%} before any use of a register name. This
|
|
is intended to let the assembler distinguish between C variables and
|
|
functions named @samp{a0} through @samp{a7}, and so on. The @samp{%} is
|
|
always accepted, but is not required for certain configurations, notably
|
|
@samp{sun3}. The @samp{--register-prefix-optional} option may be used
|
|
to permit omitting the @samp{%} even for configurations for which it is
|
|
normally required. If this is done, it will generally be impossible to
|
|
refer to C variables and functions with the same names as register
|
|
names.
|
|
|
|
@cindex @samp{--bitwise-or} option, M680x0
|
|
@item --bitwise-or
|
|
Normally the character @samp{|} is treated as a comment character, which
|
|
means that it can not be used in expressions. The @samp{--bitwise-or}
|
|
option turns @samp{|} into a normal character. In this mode, you must
|
|
either use C style comments, or start comments with a @samp{#} character
|
|
at the beginning of a line.
|
|
|
|
@cindex @samp{--base-size-default-16}
|
|
@cindex @samp{--base-size-default-32}
|
|
@item --base-size-default-16 --base-size-default-32
|
|
If you use an addressing mode with a base register without specifying
|
|
the size, @code{@value{AS}} will normally use the full 32 bit value.
|
|
For example, the addressing mode @samp{%a0@@(%d0)} is equivalent to
|
|
@samp{%a0@@(%d0:l)}. You may use the @samp{--base-size-default-16}
|
|
option to tell @code{@value{AS}} to default to using the 16 bit value.
|
|
In this case, @samp{%a0@@(%d0)} is equivalent to @samp{%a0@@(%d0:w)}.
|
|
You may use the @samp{--base-size-default-32} option to restore the
|
|
default behaviour.
|
|
|
|
@cindex @samp{--disp-size-default-16}
|
|
@cindex @samp{--disp-size-default-32}
|
|
@item --disp-size-default-16 --disp-size-default-32
|
|
If you use an addressing mode with a displacement, and the value of the
|
|
displacement is not known, @code{@value{AS}} will normally assume that
|
|
the value is 32 bits. For example, if the symbol @samp{disp} has not
|
|
been defined, @code{@value{AS}} will assemble the addressing mode
|
|
@samp{%a0@@(disp,%d0)} as though @samp{disp} is a 32 bit value. You may
|
|
use the @samp{--disp-size-default-16} option to tell @code{@value{AS}}
|
|
to instead assume that the displacement is 16 bits. In this case,
|
|
@code{@value{AS}} will assemble @samp{%a0@@(disp,%d0)} as though
|
|
@samp{disp} is a 16 bit value. You may use the
|
|
@samp{--disp-size-default-32} option to restore the default behaviour.
|
|
|
|
@cindex @samp{--pcrel}
|
|
@item --pcrel
|
|
Always keep branches PC-relative. In the M680x0 architecture all branches
|
|
are defined as PC-relative. However, on some processors they are limited
|
|
to word displacements maximum. When @code{@value{AS}} needs a long branch
|
|
that is not available, it normally emits an absolute jump instead. This
|
|
option disables this substitution. When this option is given and no long
|
|
branches are available, only word branches will be emitted. An error
|
|
message will be generated if a word branch cannot reach its target. This
|
|
option has no effect on 68020 and other processors that have long branches.
|
|
@pxref{M68K-Branch,,Branch Improvement}.
|
|
|
|
@cindex @samp{-m68000} and related options
|
|
@cindex architecture options, M680x0
|
|
@cindex M680x0 architecture options
|
|
@item -m68000
|
|
@code{@value{AS}} can assemble code for several different members of the
|
|
Motorola 680x0 family. The default depends upon how @code{@value{AS}}
|
|
was configured when it was built; normally, the default is to assemble
|
|
code for the 68020 microprocessor. The following options may be used to
|
|
change the default. These options control which instructions and
|
|
addressing modes are permitted. The members of the 680x0 family are
|
|
very similar. For detailed information about the differences, see the
|
|
Motorola manuals.
|
|
|
|
@table @samp
|
|
@item -m68000
|
|
@itemx -m68ec000
|
|
@itemx -m68hc000
|
|
@itemx -m68hc001
|
|
@itemx -m68008
|
|
@itemx -m68302
|
|
@itemx -m68306
|
|
@itemx -m68307
|
|
@itemx -m68322
|
|
@itemx -m68356
|
|
Assemble for the 68000. @samp{-m68008}, @samp{-m68302}, and so on are synonyms
|
|
for @samp{-m68000}, since the chips are the same from the point of view
|
|
of the assembler.
|
|
|
|
@item -m68010
|
|
Assemble for the 68010.
|
|
|
|
@item -m68020
|
|
@itemx -m68ec020
|
|
Assemble for the 68020. This is normally the default.
|
|
|
|
@item -m68030
|
|
@itemx -m68ec030
|
|
Assemble for the 68030.
|
|
|
|
@item -m68040
|
|
@itemx -m68ec040
|
|
Assemble for the 68040.
|
|
|
|
@item -m68060
|
|
@itemx -m68ec060
|
|
Assemble for the 68060.
|
|
|
|
@item -mcpu32
|
|
@itemx -m68330
|
|
@itemx -m68331
|
|
@itemx -m68332
|
|
@itemx -m68333
|
|
@itemx -m68334
|
|
@itemx -m68336
|
|
@itemx -m68340
|
|
@itemx -m68341
|
|
@itemx -m68349
|
|
@itemx -m68360
|
|
Assemble for the CPU32 family of chips.
|
|
|
|
@item -m5200
|
|
@item -m5202
|
|
@item -m5204
|
|
@item -m5206
|
|
@item -m5206e
|
|
@item -m521x
|
|
@item -m5249
|
|
@item -m528x
|
|
@item -m5307
|
|
@item -m5407
|
|
@item -m547x
|
|
@item -m548x
|
|
@item -mcfv4
|
|
@item -mcfv4e
|
|
Assemble for the ColdFire family of chips.
|
|
|
|
@item -m68881
|
|
@itemx -m68882
|
|
Assemble 68881 floating point instructions. This is the default for the
|
|
68020, 68030, and the CPU32. The 68040 and 68060 always support
|
|
floating point instructions.
|
|
|
|
@item -mno-68881
|
|
Do not assemble 68881 floating point instructions. This is the default
|
|
for 68000 and the 68010. The 68040 and 68060 always support floating
|
|
point instructions, even if this option is used.
|
|
|
|
@item -m68851
|
|
Assemble 68851 MMU instructions. This is the default for the 68020,
|
|
68030, and 68060. The 68040 accepts a somewhat different set of MMU
|
|
instructions; @samp{-m68851} and @samp{-m68040} should not be used
|
|
together.
|
|
|
|
@item -mno-68851
|
|
Do not assemble 68851 MMU instructions. This is the default for the
|
|
68000, 68010, and the CPU32. The 68040 accepts a somewhat different set
|
|
of MMU instructions.
|
|
@end table
|
|
@end table
|
|
|
|
@node M68K-Syntax
|
|
@section Syntax
|
|
|
|
@cindex @sc{mit}
|
|
This syntax for the Motorola 680x0 was developed at @sc{mit}.
|
|
|
|
@cindex M680x0 syntax
|
|
@cindex syntax, M680x0
|
|
@cindex M680x0 size modifiers
|
|
@cindex size modifiers, M680x0
|
|
The 680x0 version of @code{@value{AS}} uses instructions names and
|
|
syntax compatible with the Sun assembler. Intervening periods are
|
|
ignored; for example, @samp{movl} is equivalent to @samp{mov.l}.
|
|
|
|
In the following table @var{apc} stands for any of the address registers
|
|
(@samp{%a0} through @samp{%a7}), the program counter (@samp{%pc}), the
|
|
zero-address relative to the program counter (@samp{%zpc}), a suppressed
|
|
address register (@samp{%za0} through @samp{%za7}), or it may be omitted
|
|
entirely. The use of @var{size} means one of @samp{w} or @samp{l}, and
|
|
it may be omitted, along with the leading colon, unless a scale is also
|
|
specified. The use of @var{scale} means one of @samp{1}, @samp{2},
|
|
@samp{4}, or @samp{8}, and it may always be omitted along with the
|
|
leading colon.
|
|
|
|
@cindex M680x0 addressing modes
|
|
@cindex addressing modes, M680x0
|
|
The following addressing modes are understood:
|
|
@table @dfn
|
|
@item Immediate
|
|
@samp{#@var{number}}
|
|
|
|
@item Data Register
|
|
@samp{%d0} through @samp{%d7}
|
|
|
|
@item Address Register
|
|
@samp{%a0} through @samp{%a7}@*
|
|
@samp{%a7} is also known as @samp{%sp}, i.e. the Stack Pointer. @code{%a6}
|
|
is also known as @samp{%fp}, the Frame Pointer.
|
|
|
|
@item Address Register Indirect
|
|
@samp{%a0@@} through @samp{%a7@@}
|
|
|
|
@item Address Register Postincrement
|
|
@samp{%a0@@+} through @samp{%a7@@+}
|
|
|
|
@item Address Register Predecrement
|
|
@samp{%a0@@-} through @samp{%a7@@-}
|
|
|
|
@item Indirect Plus Offset
|
|
@samp{@var{apc}@@(@var{number})}
|
|
|
|
@item Index
|
|
@samp{@var{apc}@@(@var{number},@var{register}:@var{size}:@var{scale})}
|
|
|
|
The @var{number} may be omitted.
|
|
|
|
@item Postindex
|
|
@samp{@var{apc}@@(@var{number})@@(@var{onumber},@var{register}:@var{size}:@var{scale})}
|
|
|
|
The @var{onumber} or the @var{register}, but not both, may be omitted.
|
|
|
|
@item Preindex
|
|
@samp{@var{apc}@@(@var{number},@var{register}:@var{size}:@var{scale})@@(@var{onumber})}
|
|
|
|
The @var{number} may be omitted. Omitting the @var{register} produces
|
|
the Postindex addressing mode.
|
|
|
|
@item Absolute
|
|
@samp{@var{symbol}}, or @samp{@var{digits}}, optionally followed by
|
|
@samp{:b}, @samp{:w}, or @samp{:l}.
|
|
@end table
|
|
|
|
@node M68K-Moto-Syntax
|
|
@section Motorola Syntax
|
|
|
|
@cindex Motorola syntax for the 680x0
|
|
@cindex alternate syntax for the 680x0
|
|
|
|
The standard Motorola syntax for this chip differs from the syntax
|
|
already discussed (@pxref{M68K-Syntax,,Syntax}). @code{@value{AS}} can
|
|
accept Motorola syntax for operands, even if @sc{mit} syntax is used for
|
|
other operands in the same instruction. The two kinds of syntax are
|
|
fully compatible.
|
|
|
|
In the following table @var{apc} stands for any of the address registers
|
|
(@samp{%a0} through @samp{%a7}), the program counter (@samp{%pc}), the
|
|
zero-address relative to the program counter (@samp{%zpc}), or a
|
|
suppressed address register (@samp{%za0} through @samp{%za7}). The use
|
|
of @var{size} means one of @samp{w} or @samp{l}, and it may always be
|
|
omitted along with the leading dot. The use of @var{scale} means one of
|
|
@samp{1}, @samp{2}, @samp{4}, or @samp{8}, and it may always be omitted
|
|
along with the leading asterisk.
|
|
|
|
The following additional addressing modes are understood:
|
|
|
|
@table @dfn
|
|
@item Address Register Indirect
|
|
@samp{(%a0)} through @samp{(%a7)}@*
|
|
@samp{%a7} is also known as @samp{%sp}, i.e. the Stack Pointer. @code{%a6}
|
|
is also known as @samp{%fp}, the Frame Pointer.
|
|
|
|
@item Address Register Postincrement
|
|
@samp{(%a0)+} through @samp{(%a7)+}
|
|
|
|
@item Address Register Predecrement
|
|
@samp{-(%a0)} through @samp{-(%a7)}
|
|
|
|
@item Indirect Plus Offset
|
|
@samp{@var{number}(@var{%a0})} through @samp{@var{number}(@var{%a7})},
|
|
or @samp{@var{number}(@var{%pc})}.
|
|
|
|
The @var{number} may also appear within the parentheses, as in
|
|
@samp{(@var{number},@var{%a0})}. When used with the @var{pc}, the
|
|
@var{number} may be omitted (with an address register, omitting the
|
|
@var{number} produces Address Register Indirect mode).
|
|
|
|
@item Index
|
|
@samp{@var{number}(@var{apc},@var{register}.@var{size}*@var{scale})}
|
|
|
|
The @var{number} may be omitted, or it may appear within the
|
|
parentheses. The @var{apc} may be omitted. The @var{register} and the
|
|
@var{apc} may appear in either order. If both @var{apc} and
|
|
@var{register} are address registers, and the @var{size} and @var{scale}
|
|
are omitted, then the first register is taken as the base register, and
|
|
the second as the index register.
|
|
|
|
@item Postindex
|
|
@samp{([@var{number},@var{apc}],@var{register}.@var{size}*@var{scale},@var{onumber})}
|
|
|
|
The @var{onumber}, or the @var{register}, or both, may be omitted.
|
|
Either the @var{number} or the @var{apc} may be omitted, but not both.
|
|
|
|
@item Preindex
|
|
@samp{([@var{number},@var{apc},@var{register}.@var{size}*@var{scale}],@var{onumber})}
|
|
|
|
The @var{number}, or the @var{apc}, or the @var{register}, or any two of
|
|
them, may be omitted. The @var{onumber} may be omitted. The
|
|
@var{register} and the @var{apc} may appear in either order. If both
|
|
@var{apc} and @var{register} are address registers, and the @var{size}
|
|
and @var{scale} are omitted, then the first register is taken as the
|
|
base register, and the second as the index register.
|
|
@end table
|
|
|
|
@node M68K-Float
|
|
@section Floating Point
|
|
|
|
@cindex floating point, M680x0
|
|
@cindex M680x0 floating point
|
|
Packed decimal (P) format floating literals are not supported.
|
|
Feel free to add the code!
|
|
|
|
The floating point formats generated by directives are these.
|
|
|
|
@table @code
|
|
@cindex @code{float} directive, M680x0
|
|
@item .float
|
|
@code{Single} precision floating point constants.
|
|
|
|
@cindex @code{double} directive, M680x0
|
|
@item .double
|
|
@code{Double} precision floating point constants.
|
|
|
|
@cindex @code{extend} directive M680x0
|
|
@cindex @code{ldouble} directive M680x0
|
|
@item .extend
|
|
@itemx .ldouble
|
|
@code{Extended} precision (@code{long double}) floating point constants.
|
|
@end table
|
|
|
|
@node M68K-Directives
|
|
@section 680x0 Machine Directives
|
|
|
|
@cindex M680x0 directives
|
|
@cindex directives, M680x0
|
|
In order to be compatible with the Sun assembler the 680x0 assembler
|
|
understands the following directives.
|
|
|
|
@table @code
|
|
@cindex @code{data1} directive, M680x0
|
|
@item .data1
|
|
This directive is identical to a @code{.data 1} directive.
|
|
|
|
@cindex @code{data2} directive, M680x0
|
|
@item .data2
|
|
This directive is identical to a @code{.data 2} directive.
|
|
|
|
@cindex @code{even} directive, M680x0
|
|
@item .even
|
|
This directive is a special case of the @code{.align} directive; it
|
|
aligns the output to an even byte boundary.
|
|
|
|
@cindex @code{skip} directive, M680x0
|
|
@item .skip
|
|
This directive is identical to a @code{.space} directive.
|
|
@end table
|
|
|
|
@need 2000
|
|
@node M68K-opcodes
|
|
@section Opcodes
|
|
|
|
@cindex M680x0 opcodes
|
|
@cindex opcodes, M680x0
|
|
@cindex instruction set, M680x0
|
|
@c doc@cygnus.com: I don't see any point in the following
|
|
@c paragraph. Bugs are bugs; how does saying this
|
|
@c help anyone?
|
|
@ignore
|
|
Danger: Several bugs have been found in the opcode table (and
|
|
fixed). More bugs may exist. Be careful when using obscure
|
|
instructions.
|
|
@end ignore
|
|
|
|
@menu
|
|
* M68K-Branch:: Branch Improvement
|
|
* M68K-Chars:: Special Characters
|
|
@end menu
|
|
|
|
@node M68K-Branch
|
|
@subsection Branch Improvement
|
|
|
|
@cindex pseudo-opcodes, M680x0
|
|
@cindex M680x0 pseudo-opcodes
|
|
@cindex branch improvement, M680x0
|
|
@cindex M680x0 branch improvement
|
|
Certain pseudo opcodes are permitted for branch instructions.
|
|
They expand to the shortest branch instruction that reach the
|
|
target. Generally these mnemonics are made by substituting @samp{j} for
|
|
@samp{b} at the start of a Motorola mnemonic.
|
|
|
|
The following table summarizes the pseudo-operations. A @code{*} flags
|
|
cases that are more fully described after the table:
|
|
|
|
@smallexample
|
|
Displacement
|
|
+------------------------------------------------------------
|
|
| 68020 68000/10, not PC-relative OK
|
|
Pseudo-Op |BYTE WORD LONG ABSOLUTE LONG JUMP **
|
|
+------------------------------------------------------------
|
|
jbsr |bsrs bsrw bsrl jsr
|
|
jra |bras braw bral jmp
|
|
* jXX |bXXs bXXw bXXl bNXs;jmp
|
|
* dbXX | N/A dbXXw dbXX;bras;bral dbXX;bras;jmp
|
|
fjXX | N/A fbXXw fbXXl N/A
|
|
|
|
XX: condition
|
|
NX: negative of condition XX
|
|
|
|
@end smallexample
|
|
@center @code{*}---see full description below
|
|
@center @code{**}---this expansion mode is disallowed by @samp{--pcrel}
|
|
|
|
@table @code
|
|
@item jbsr
|
|
@itemx jra
|
|
These are the simplest jump pseudo-operations; they always map to one
|
|
particular machine instruction, depending on the displacement to the
|
|
branch target. This instruction will be a byte or word branch is that
|
|
is sufficient. Otherwise, a long branch will be emitted if available.
|
|
If no long branches are available and the @samp{--pcrel} option is not
|
|
given, an absolute long jump will be emitted instead. If no long
|
|
branches are available, the @samp{--pcrel} option is given, and a word
|
|
branch cannot reach the target, an error message is generated.
|
|
|
|
In addition to standard branch operands, @code{@value{AS}} allows these
|
|
pseudo-operations to have all operands that are allowed for jsr and jmp,
|
|
substituting these instructions if the operand given is not valid for a
|
|
branch instruction.
|
|
|
|
@item j@var{XX}
|
|
Here, @samp{j@var{XX}} stands for an entire family of pseudo-operations,
|
|
where @var{XX} is a conditional branch or condition-code test. The full
|
|
list of pseudo-ops in this family is:
|
|
@smallexample
|
|
jhi jls jcc jcs jne jeq jvc
|
|
jvs jpl jmi jge jlt jgt jle
|
|
@end smallexample
|
|
|
|
Usually, each of these pseudo-operations expands to a single branch
|
|
instruction. However, if a word branch is not sufficient, no long branches
|
|
are available, and the @samp{--pcrel} option is not given, @code{@value{AS}}
|
|
issues a longer code fragment in terms of @var{NX}, the opposite condition
|
|
to @var{XX}. For example, under these conditions:
|
|
@smallexample
|
|
j@var{XX} foo
|
|
@end smallexample
|
|
gives
|
|
@smallexample
|
|
b@var{NX}s oof
|
|
jmp foo
|
|
oof:
|
|
@end smallexample
|
|
|
|
@item db@var{XX}
|
|
The full family of pseudo-operations covered here is
|
|
@smallexample
|
|
dbhi dbls dbcc dbcs dbne dbeq dbvc
|
|
dbvs dbpl dbmi dbge dblt dbgt dble
|
|
dbf dbra dbt
|
|
@end smallexample
|
|
|
|
Motorola @samp{db@var{XX}} instructions allow word displacements only. When
|
|
a word displacement is sufficient, each of these pseudo-operations expands
|
|
to the corresponding Motorola instruction. When a word displacement is not
|
|
sufficient and long branches are available, when the source reads
|
|
@samp{db@var{XX} foo}, @code{@value{AS}} emits
|
|
@smallexample
|
|
db@var{XX} oo1
|
|
bras oo2
|
|
oo1:bral foo
|
|
oo2:
|
|
@end smallexample
|
|
|
|
If, however, long branches are not available and the @samp{--pcrel} option is
|
|
not given, @code{@value{AS}} emits
|
|
@smallexample
|
|
db@var{XX} oo1
|
|
bras oo2
|
|
oo1:jmp foo
|
|
oo2:
|
|
@end smallexample
|
|
|
|
@item fj@var{XX}
|
|
This family includes
|
|
@smallexample
|
|
fjne fjeq fjge fjlt fjgt fjle fjf
|
|
fjt fjgl fjgle fjnge fjngl fjngle fjngt
|
|
fjnle fjnlt fjoge fjogl fjogt fjole fjolt
|
|
fjor fjseq fjsf fjsne fjst fjueq fjuge
|
|
fjugt fjule fjult fjun
|
|
@end smallexample
|
|
|
|
Each of these pseudo-operations always expands to a single Motorola
|
|
coprocessor branch instruction, word or long. All Motorola coprocessor
|
|
branch instructions allow both word and long displacements.
|
|
|
|
@end table
|
|
|
|
@node M68K-Chars
|
|
@subsection Special Characters
|
|
|
|
@cindex special characters, M680x0
|
|
@cindex M680x0 immediate character
|
|
@cindex immediate character, M680x0
|
|
@cindex M680x0 line comment character
|
|
@cindex line comment character, M680x0
|
|
@cindex comments, M680x0
|
|
The immediate character is @samp{#} for Sun compatibility. The
|
|
line-comment character is @samp{|} (unless the @samp{--bitwise-or}
|
|
option is used). If a @samp{#} appears at the beginning of a line, it
|
|
is treated as a comment unless it looks like @samp{# line file}, in
|
|
which case it is treated normally.
|
|
|